this thread is giving me mindgasms... i love this kind of stuff XD
...and random thought based on the idea of time dilation (didn't know much about it at all til reading this)...assuming we had ships that could travel 99.9% speed of light (or however close) wouldn't that, in a sense, be like time travel? i mean, say you take a round trip going in one of these ships to... any random spot far from earth, and then back. Say this trip lasts a week for the ship, when the people come out of the ship back on earth it will have been years.
a problem with this might be the thought of being able to curve accurately back to earth going this speed, cause going in a straight line, stopping, then going straight back may seem ridiculous... or maybe not XD i'm not sure, but it came to mind after reading some of the things here
Time travel to the future is absolutely possible, to the past is absolutely impossible. Ideally you would be circling a massive planet such as Jupiter at incredible speeds to conserve fuel.
Say this trip lasts a week for the ship, when the people come out of the ship back on earth it will have been years.
Yup. Forwards time travel is possible. Just go really really fast for a really long time.
Stephen Hawking proposed just going into orbit around a black hole. Zip around close to the speed of light for awhile, then break orbit, head home, and tens of thousands of years will have passed.
Backwards time travel, however, is very likely not possible.
Say this trip lasts a week for the ship, when the people come out of the ship back on earth it will have been years.
Yup. Forwards time travel is possible. Just go really really fast for a really long time.
Stephen Hawking proposed just going into orbit around a black hole. Zip around close to the speed of light for awhile, then break orbit, head home, and tens of thousands of years will have passed.
Backwards time travel, however, is very likely not possible.
unless you are a subscriber to string theory, since cosmic strings would ignore the rules of standard space time you could theoredically use them to travel back in time. But since cosmic strings would be microscopic it may only be possible to send a transmission back in time using one.
You could conceivably "travel into the past" through a wormhole, but it's not... really time travel. Let's say I'm on planet A and you're on planet B. You broadcast a "I'm on my way!" message, and it sets off towards me at the speed of light. Then you warp to me through a wormhole. You have now arrived before your "I'm on my way!" message gets to me, so from my perspective, you arrived before you departed.
Similarly, earth is about 4.7 billion years old. If you could teleport yourself through a wormhole to a planet over 4.7 billion light years away, you could turn on your super powerful telescope and "watch" the unfolding of human history all over again, from the birth of our star through the present. Depending on your definition, you've traveled into the past.
But that's not really "backwards time travel" as people imagine it, so it doesn't satisfy the requirements in most people's heads.
It just means that any trip to another star is likely going to involve several generations, one or more of which is born in space.
You will end up with more people arriving than originally departed, or you're going to be in trouble once you get there. =)
And for trips longer than a human lifespan, well... you have to set off knowing you're never going to get there, but your grandchildren might.
There are other things to take into consideration if it's the initial flight though. Like what effects could travel take on fetuses during the gestation period?
How do you anticipate the needs (food, waste disposal, medical supplies, blah, blah, blah...) for a population that is undetermined at the time of departure?
EDIT: I see someone already covered the "sex without gravity" question.
I always kinda assumed we'd pull off long term self sustainable space travel long before we make it to another inhabitable planet. One-way ticket to the planet, sure, but the idea of some weird Macross-style artificial biome sounds like a decent last resort if we ever... y'know, screw up whatever's left of Earth.
Other than the depressing idea of spending countless generations on a space craft, I'm sure there's way more logical challenges to the idea.
How do you anticipate the needs (food, waste disposal, medical supplies, blah, blah, blah...) for a population that is undetermined at the time of departure?
EDIT: I see someone already covered the "sex without gravity" question.
Basically a ship the size of a city
A lot of math
this ship could never be build on earth or any planet with strong gravitational forces.
The moon for an example might be possible to engineer something of this magnitude
A ship can be build that rotates on a central axis making artificial gravity, this is easy to do and can be spun at anywhere from .1-10Gs, for space travel to a planet with different gravity then our own adjustments could be made to slowly adjust the gravity to match that of the destination over the course of the entire trip.
It's just a shame Obama pretty much shut down our space program.
Sorry if it's been said as I haven't read through the thread yet, but I think the space program should be halted. The funding for it is better used to develop new propulsion systems or extend human life exponentially (not only with medicine but also theories like transhumanism). That will allow our greatest minds to continue working on developing technology that could actually get our race somewhere. Shooting out probes with little new technology is pointless especially given the economy.
You could conceivably "travel into the past" through a wormhole, but it's not... really time travel. Let's say I'm on planet A and you're on planet B. You broadcast a "I'm on my way!" message, and it sets off towards me at the speed of light. Then you warp to me through a wormhole. You have now arrived before your "I'm on my way!" message gets to me, so from my perspective, you arrived before you departed.
Similarly, earth is about 4.7 billion years old. If you could teleport yourself through a wormhole to a planet over 4.7 billion light years away, you could turn on your super powerful telescope and "watch" the unfolding of human history all over again, from the birth of our star through the present. Depending on your definition, you've traveled into the past.
But that's not really "backwards time travel" as people imagine it, so it doesn't satisfy the requirements in most people's heads.
I subscribe to M theory myself.. You can conceivably travel to the 'past' without actually ever going back in time.. You could arrive to a planet exactly like Earth, only 10, 20, 50, 100, etc years in what is 'our past' but is their current present. It's also one of the best ways around stuff like the grandfather paradox..
In conventional time travel (where you could travel it like a street or sidewalk, you can go backwards or forwards) this poses a huge problem, because if you go back in time and kill your grandfather before your father was conceived, you would have never existed to go back and do it in the first place.. However in M-theory, since you're just traveling to a different universe, no matter how much like ours it may be, it's still not the one you were made in.. So you can kill the man that would eventually be your grandfather, with no special effects like vanishing in a puff a smoke as soon as you do..
It also explains some other things that we don't really understand, but are absolutely core to our world and surroundings, like gravity for example.. You have the weight of the entire planet weighing down on you (pulling you down) but you are still able to jump, not to mention exist.. Gravity as we know it is a very weak force, even though it shouldn't be, one theory is that gravity is actually shared by multiple different universes, and that's why it's so weak.
It's just a shame Obama pretty much shut down our space program.
Sorry if it's been said as I haven't read through the thread yet, but I think the space program should be halted. The funding for it is better used to develop new propulsion systems or extend human life exponentially (not only with medicine but also theories like transhumanism). That will allow our greatest minds to continue working on developing technology that could actually get our race somewhere. Shooting out probes with little new technology is pointless especially given the economy.
I would prefer we fund a full mapping of PEI asteroids and the building of a massive railgun on the moon to shoot any potental hits away from us. By massive i mean a launcher that can hurl a rock out about the size of rhode island (dont ask me where will find the rocks...)
Gravity as we know it is a very weak force, even though it shouldn't be, one theory is that gravity is actually shared by multiple different universes, and that's why it's so weak.
Yup, parallel universes in M theory fixes a whole lot of things, including backwards time travel and the problem with gravity.
Everyone thinks gravity is such a huge force, but they think nothing of a 1 inch magnet being able to pick a paperclip off your desk.
The electromagnetic force from that 1 inch magnet just "won" versus all the gravity in the entire planet underneath you.
But put that into some perspective as well, it has a lot more going on than simple force lines. The gravity of the sun can exert incredible influence on the planets over vast (in human terms) expanses of space. Black holes, supposedly, form the centers of galaxies. There are a lot of forces at work in the universe, and they work differently at different scales.
You could conceivably "travel into the past" through a wormhole, but it's not... really time travel. Let's say I'm on planet A and you're on planet B. You broadcast a "I'm on my way!" message, and it sets off towards me at the speed of light. Then you warp to me through a wormhole. You have now arrived before your "I'm on my way!" message gets to me, so from my perspective, you arrived before you departed.
Similarly, earth is about 4.7 billion years old. If you could teleport yourself through a wormhole to a planet over 4.7 billion light years away, you could turn on your super powerful telescope and "watch" the unfolding of human history all over again, from the birth of our star through the present. Depending on your definition, you've traveled into the past.
But that's not really "backwards time travel" as people imagine it, so it doesn't satisfy the requirements in most people's heads.
I subscribe to M theory myself.. You can conceivably travel to the 'past' without actually ever going back in time.. You could arrive to a planet exactly like Earth, only 10, 20, 50, 100, etc years in what is 'our past' but is their current present. It's also one of the best ways around stuff like the grandfather paradox..
In conventional time travel (where you could travel it like a street or sidewalk, you can go backwards or forwards) this poses a huge problem, because if you go back in time and kill your grandfather before your father was conceived, you would have never existed to go back and do it in the first place.. However in M-theory, since you're just traveling to a different universe, no matter how much like ours it may be, it's still not the one you were made in.. So you can kill the man that would eventually be your grandfather, with no special effects like vanishing in a puff a smoke as soon as you do..
It also explains some other things that we don't really understand, but are absolutely core to our world and surroundings, like gravity for example.. You have the weight of the entire planet weighing down on you (pulling you down) but you are still able to jump, not to mention exist.. Gravity as we know it is a very weak force, even though it shouldn't be, one theory is that gravity is actually shared by multiple different universes, and that's why it's so weak.
Thanks Eugene, Jaerik and Kirana by the way. I missed the boat on theoretical and abstract physics just because this was hardly mandatory for me during college. Practical physics are kind of what I'm consumed with. LOL!
This subject matter is pretty astounding though.
EDIT: Glad this article popped up! Unfortunately, FFXIAH has been lacking brain food for a good week or so.
Thanks Eugene, Jaerik and Kirana by the way. I missed the boat on theoretical and abstract physics just because this was hardly mandatory for me during college. Practical physics are kind of what I'm consumed with. LOL!
This subject matter is pretty astounding though.
EDIT: Glad this article popped up! Unfortunately, FFXIAH has been lacking brain food for a good week or so.
I'm glad you popped up! ;)
LOL, jk.
I love lurking these brain food threads. :3
Thanks Eugene, Jaerik and Kirana by the way. I missed the boat on theoretical and abstract physics just because this was hardly mandatory for me during college. Practical physics are kind of what I'm consumed with. LOL!
This subject matter is pretty astounding though.
EDIT: Glad this article popped up! Unfortunately, FFXIAH has been lacking brain food for a good week or so.
I'm glad you popped up! ;)
LOL, jk.
I love lurking these brain food threads. :3
Glad you did too! How are you feeling?
I have nothing to contribute to astro-physics and what not, but my imagination has been running a little wild with the possible sociological and biological scenarios, and of course adaptation leads to evolution...
I missed the boat on theoretical and abstract physics just because this was hardly mandatory for me during college.
I would have too but a friend of mine freshman year of college took a course in astrophysics. I sat in on a couple of his classes on the days I had off just to see how the universe worked, and I was really fascinated with conceptual models of the universe. :)
In regards to backwards time travel through wormholes, it may be possible to travel backwards in time if you view the fabric of space and time as one entity. We know it is possible to bend space, and if space-time really is one entity, then it follows we can bend time as well. If you were able to tunnel through bent space, it may be possible to tunnel through bent time. So in the process of bending space in a worm hole, we could bend time, possibly reaching into the past.
And I thought I was the Negative Nancy on this subject matter!?! LOL!
More of this subject, please!!!
The iconic Morgan Freeman returns to SCIENCE (channel) on Wednesday, June 8, at 9:00 PM (ET/PT) for a second season of the breakthrough series, THROUGH THE WORMHOLE WITH MORGAN FREEMAN.
I missed the boat on theoretical and abstract physics just because this was hardly mandatory for me during college.
I would have too but a friend of mine freshman year of college took a course in astrophysics. I sat in on a couple of his classes on the days I had off just to see how the universe worked, and I was really fascinated with conceptual models of the universe. :)
In regards to backwards time travel through wormholes, it may be possible to travel backwards in time if you view the fabric of space and time as one entity. We know it is possible to bend space, and if space-time really is one entity, then it follows we can bend time as well. If you were able to tunnel through bent space, it may be possible to tunnel through bent time. So in the process of bending space in a worm hole, we could bend time, possibly reaching into the past.
Totally off the subject, but I remember sitting in on one of my HS sweetheart's classes when I went to visit him our freshman year of college. (He was CS, so it was Boolean Algebra.) I had perma-"duh"-face throughout the whole ordeal, and afterwards, not only did I get a barrage of girls and math jokes, but blonde jokes thrown at me too!
I've always been great at practical maths, but the abstract maths blow my mind.
EDIT: I can laugh about that moment now, but I wanted to stab him in the eyeball that day! LOL!
I used to like Michio Kaku as well, but he's become such a media ***, and so many of his shows now contain so little actual science, I mostly groan whenever he makes an appearance.
The iconic Morgan Freeman returns to SCIENCE (channel) on Wednesday, June 8, at 9:00 PM (ET/PT) for a second season of the breakthrough series, THROUGH THE WORMHOLE WITH MORGAN FREEMAN.
Everything is explained the way Jaerik does.
Not really related, but I swear Morgan Freeman is a living Siren. If I were a mariner, that voice would definitely lead me to my death on a rocky atoll.
Lakshmi.Jaerik said:
Brian Cox is awesome.
I used to like Michio Kaku as well, but he's become such a media ***, and so many of his shows now contain so little actual science, I mostly groan whenever he makes an appearance.
Neil deGrasse Tyson does a pretty good job too.
Michio got all facebook over night... At first it was about presenting the science in simple terms (something only true geniuses can do), but now it's just about showing off his wavy hair.
I have to admit, i know nothing in this field of study and i just really found it an incredible thought that a journey of a few months would have caused a passing of actual thousands of years elsewhere?!
Damn.
Pretty much the best shot you have for colonization is say goodbye to everything you know and hope that the place your going remains in tact as you hoped for that long lol.
Twenty Light-years away, a veritable "Stone's throw" in an astronomical sense, lies Gliese 581, and the fourth planet, dubbed Gliese 581d (They're astronomers, not writers) is (one of several actually, but this is the interesting one) a planet that falls into the habitable zone for it's star.
FrenchAstronmers said:
"With a dense carbon dioxide atmosphere - a likely scenario on such a large planet - the climate of Gliese 581d is not only stable against collapse but warm enough to have oceans, clouds and rainfall,"
Gliese 581d is believed to have a mass around 7times that of Earth, but a lower rotational velocity results in a gravity of about twice that of Earth.
FrenchAstronmers said:
"The denser air and thick clouds would keep the surface in a perpetual murky red twilight, and its large mass means that surface gravity would be around double that on Earth,"
Two things strike me as peculiar, first has already been said, this Planet is actually very close to us. While it would still take 300,000Years to arrive using conventional propulsion, on a cosmic scale, it might as well be down the block.
Second, Gliese581(The star) is a Red Dwarf (Tiny, with low output), Red Dwarf stars are not exactly the powerhouse of fusion our Star is, it was originally thought that the likeihood of planets forming within a Red Dwarfs theoretical habitation zone was beyond unlikely, and damn near impossible, once again showing the world, that when dealing with things on a galactic scale, there's no such thing as a statistical impossibility.
It's just a shame Obama pretty much shut down our space program.
